Ive made quite good holes using a coke can a pin and 1200 grit sanding paper. .3mm is quite easy, but I use EMS laser pinholes that a friend form the US sent me. Will the laser you have access to do a single .3mm hole? if so get some thin brass or copper shimming material and whack a hole in it...
Here how to do your own http://withoutlenses.com/view/drill-your-own
I would definitely try the engraving laser just to see if it can be done. What is the smallest spot you can make with that laser? Get some 0.001 inch thick brass or stainless steel shim stock and see if you can burn a tiny little hole. Last time I bought shim stock was from http://www.smallparts.com but since they turned into an Amazon store I have no idea if they still carry stuff like this. I would expect McMaster-Carr (http://www.mcmaster.com) will also have this, and maybe http://www.onlinemetals.com might have shim stock.
The thinner the metal, the better the pinholes. The brass will be fairly fragile so be careful. The stainless should be relatively robust (considering the thickness we are talking about).
Attached is a generic plan for a pinhole design which I currently use. Being cupped outward allows you to burnish the plate down to minimal thickness at the pinhole. The thickness of the material that makes the pinhole is a critical parameter which is sometimes overlooked by the pinholer.
Another area that can be overlooked is that a pinhole that is too small is just as bad as a pinhole that is too big. That is, if you are concerned with image sharpness.
Last edited by DannL; 06-28-2009 at 01:13 AM. Click to view previous post history.
"Lo único de lo que el mundo no se cansará nunca es de exageración." Salvador Dalí
To get 15.8 feet, I multiplied 746.5 by 10 to get 74.65cm. I then divided 74.65 by 2.54 to get 29.38in.
That should actually say "to get 29.38in." I was trying to correct a mistake in math by taking out the numbers I screwed up and replacing them with the right ones. I just now caught that I didnt get the first 15.8 feet part. The edit button wasnt under the post tonight, and I dont know why :/
Here you go, no math involved. Glued a board in a 1 gal. paint can to hold the paper negative flat. Sprayed the inside of the can with flat black paint. Drilled a hole in the can with a #72 drill bit (I think) and the sanded with 400 grit sand paper to remove the burrs and hopefully thin the metal a bit. Here a an image from the camera (contact print from paper negative). http://www.pinholeday.org/gallery/2008/index.php?id=382